Device, system, and method for promoting patient compliance with a prescribed lower extremity partial weight-bearing rehabilitation program

ABSTRACT

In one aspect, an electronic device for promoting proper use of a walking aid during lower extremity injury rehabilitation comprises at least one load sensor configured to measure a load on the walking aid. A memory stores rehabilitation program data defining at least one time interval of a rehabilitation period and, for each time interval, a target load for the walking aid during the time interval. A currently operative time interval of the at least one time interval of the rehabilitation period is identified. Data is received, from the load sensor(s), indicative of a dynamic load on the walking aid during a patient step. Based upon the received data, a peak load upon the walking aid during the patient step is determined. A user notification indicating that the peak load is non-compliant with the target load for the walking aid for the currently operative time interval is provided.

TECHNICAL FIELD

The present disclosure relates to device, system, and method forpromoting patient compliance with a prescribed lower extremity partialweight-bearing rehabilitation program.

BACKGROUND

A lower extremity injury, such as trauma to or surgery upon a toe, foot,ankle, calf, knee, thigh, or hip, may require rehabilitation to promoteproper healing. Rehabilitation typically involves walking with theassistance of a walking aid that bears at least part of the weight ofthe user, such as a crutch, a pair of crutches, a cane, a pair of canes,or a walker.

Rehabilitation is typically performed according to a rehabilitationprogram prescribed by a doctor or other medical professional. Therehabilitation program may span multiple weeks and may have one or morephases. During each phase, a different partial weight-bearing (load)target may be prescribed for the injured lower extremity. The targetload may be expressed as a fraction of a peak load normally placed uponthe lower extremity while walking, which is 100% of the person's weight.

A medical professional may customize the parameters of a rehabilitationprogram, such as its duration, number of phases, and the target load foreach phase. The parameters may be specific to the type of lowerextremity injury that has been suffered.

In one example, a rehabilitation program for a patient with a heelfracture may have only one phase spanning four weeks, specifying atarget load of 30% of the patient's weight on the injured leg throughoutthe four-week period.

In another example, a rehabilitation program for a patient who hasrecently undergone hip replacement surgery may have three phasesspanning seven weeks, as follows:

-   -   Phase 1: three weeks of 0% load on the injured hip; then    -   Phase 2: two weeks of a 30% load on the injured hip; then    -   Phase 3: two weeks of a progressively increasing load on the        injured hip, starting at 30% load and increasing steadily to        70%.

Historically, patients have had difficulty complying with the targetloads of lower extremity rehabilitation programs. The reason is thatcommonly used rehabilitation techniques do not provide patients withsuitable tools for accurately judging a degree of load being placed upona lower extremity as the patient walks.

For example, a common approach for training a patient to apply a partialweighting target to an injured lower extremity involves the use of ascale, e.g., a common bathroom scale. The patient may be asked to steponto the scale using the injured leg while suspending the other leg andpartially supporting himself or herself on a pair of crutches whose tipsare on the floor. The patient may then be asked to lean more heavily orless heavily on the crutches until a target load on the injured leg isachieved. The target weight reading on the scale will depend on thepatient's weight. For example, for a patient weighing 200 lbs. toachieve 40% weighting on the injured leg, the scale should read 80pounds.

Such training may be repeated several times to encourage the patient toremember what the target percentage weighting on the injured leg feelslike. The patient may then be asked to simply do his or her best toreplicate that same feeling during day-to-day use of the crutches, tocomply with the target load during rehabilitation.

Yet, limitations in human perception can undermine attempts by even themost well-intentioned patients to comply with weight-bearing targets byfeel. For example, sensation in an injured lower extremity may changeover time for various reasons. One reason may be that perceived painlevels drop as the injury heals. Another reason may be that sensation inthe injured extremity may change over the course of a day, e.g., as apatient becomes fatigued. Such changes in sensation may alter thepatient's perception of the amount of weight being applied to theinjured lower extremity. This altered perception may cause the patientto unknowingly apply an improper load, be it too low or too high, on theinjured lower extremity. Improper loading may disadvantageously prolongrecovery times or may risk re-injuring the lower extremity.

Patient compliance with partial weight-bearing targets may be even moredifficult to achieve when a rehabilitation program specifies a targetload that changes over time, such as in the hip replacement exampleabove. Just when a patient has become accustomed to the feel of onetarget load, he or she may be asked to comply with a new, differenttarget load with which the patient may not be readily familiar in termsof feel.

Even if a device were available that could dynamically measure a weightapplied to an injured lower extremity in relation to a target weight,such a device would be impractical if periodic reprogramming wererequired to accommodate a changing weight-bearing target load over thecourse of a rehabilitation program.

SUMMARY

In one aspect, there is provided an electronic device for promotingproper use of a walking aid during patient rehabilitation from a lowerextremity injury, the device comprising: at least one load sensorconfigured to measure a load on the walking aid; a memory that, duringdevice operation, stores rehabilitation program data defining: at leastone time interval of a rehabilitation period; and for each of the atleast one time interval, a target load for the walking aid during thetime interval; a processor, communicatively coupled to the memory and tothe at least one load sensor, operable to: identify a currentlyoperative time interval of the at least one time interval of therehabilitation period; receive, from the at least one load sensor, dataindicative of a dynamic load on the walking aid during a patient step;determine, based upon the received data, a peak load upon the walkingaid during the patient step; and provide a user notification indicatingthat the peak load upon the walking aid during the patient step isnon-compliant with the target load for the walking aid for the currentlyoperative time interval.

In another aspect, there is provided A system for promoting proper useof a walking aid during patient rehabilitation from a lower extremityinjury, the system comprising: an electronic device associated with thewalking aid, the electronic device comprising: at least one load sensorconfigured to measure a load on the walking aid; and a processorcommunicatively coupled to the at least one load sensor; a computingdevice comprising a processor and memory storing instructions that, whenexecuted, cause the computing device to: receive rehabilitation programparameter data originating from a medical professional, therehabilitation program parameter data including, for each of a pluralityof time intervals spanning a rehabilitation period, a target relativeload for an injured lower extremity during the time interval, the targetrelative load being relative to a patient body weight; receive anindication of the patient body weight; based on the rehabilitationprogram parameter data and the patient body weight, calculate, for eachof the plurality of time intervals spanning the rehabilitation period, atarget absolute load for the walking aid during the time interval; andoutput rehabilitation program data comprising a schedule for use by theelectronic device associated with the walking aid, the schedulespecifying: the plurality of time intervals spanning the rehabilitationperiod; and for each of the plurality of time intervals spanning therehabilitation period, a target absolute load for the walking aid duringthe time interval, wherein the processor of the electronic device isoperable to automatically adjust, according to the schedule, a currentlyoperative target absolute load on the walking aid by, periodicallyduring the rehabilitation period: based on a current date, identifyingone of the time intervals of the schedule as currently operative; usingthe at least one load sensor, determining a peak load on the walking aidduring a patient step taken during the currently operative timeinterval; and providing a user notification indicating that the peakload upon the walking aid during the patient step is non-compliant withthe target absolute load on the walking aid during the currentlyoperative time interval.

In yet another aspect, there is provided a method of promoting properuse of a walking aid during patient rehabilitation from a lowerextremity injury, the method comprising: receiving rehabilitationprogram parameter data originating from a medical professional, therehabilitation program parameter data including, for each of a pluralityof time intervals spanning a rehabilitation period, a target relativeload on an injured lower extremity during the time interval, the targetrelative load being relative to a patient body weight; receiving anindication of the patient body weight; based on the rehabilitationprogram parameter data and the patient body weight, calculating, foreach of the plurality of time intervals spanning the rehabilitationperiod, a target absolute load on the walking aid during the timeinterval; and generating rehabilitation program data comprising aschedule specifying: the plurality of time intervals spanning therehabilitation period; and for each of the plurality of time intervalsspanning the rehabilitation period, a target absolute load on thewalking aid during the time interval, and at an electronic deviceassociated with the walking aid, the electronic device having at leastone load sensor operable to measure a dynamic load on the walking aid,automatically adjusting, according to the schedule, a currentlyoperative target absolute load on the walking aid by, periodicallyduring the rehabilitation period: based on a current date, identifyingone of the time intervals of the schedule as currently operative; usingthe at least one load sensor, determining a peak load on the walking aidduring a patient step taken during the currently operative timeinterval; and providing a user notification indicating that the peakload upon the walking aid during the patient step is non-compliant withthe target absolute load on the walking aid during the currentlyoperative time interval.

BRIEF DESCRIPTION OF THE DRAWINGS

In the figures which illustrate example embodiments,

FIG. 1 is a schematic diagram of an example system for promoting properuse of a during lower extremity rehabilitation;

FIG. 2 is a schematic diagram depicting the gait of a patient having aninjured left leg walking with the assistance a pair of crutches;

FIG. 3 is a perspective view of one of the smart crutch tip electronicdevices of FIG. 1 ;

FIG. 4 is an elevation view of the smart crutch tip electronic device ofFIG. 3 ;

FIG. 5 is a primarily cross-sectional view of the smart crutch tipelectronic device of FIG. 4 taken along line 5-5;

FIG. 6 is an exploded view of the smart crutch tip electronic device ofFIG. 4 ;

FIG. 7 is a simplified schematic cross-section of a lower portion of thesmart crutch tip electronic device of FIG. 4 ;

FIG. 8 depicts a graphical user interface (GUI) displayed by a mobilepatient software application at a patient mobile device of FIG. 1 ;

FIG. 9 depicts a GUI displayed by a mobile doctor software applicationat a doctor mobile device of FIG. 1 ;

FIG. 10 depicts a data structure used at a primary smart crutch tipelectronic device of FIG. 1 ;

FIG. 11 is a perspective view of the smart crutch tip devices of FIG. 1installed onto crutches and ready for use;

FIG. 12 is a flowchart of operation of the primary smart crutch tip ofFIG. 1 for monitoring compliance with a currently operative target load;

FIG. 13 is a flowchart providing detail regarding one of the operationsof FIG. 12 in the case where the walking aid comprises two crutches;

FIG. 14 is a flowchart providing detail regarding another one of theoperations of FIG. 12 in the case where the walking aid comprises twocrutches;

FIG. 15A is a line graph depicting the dynamic load on a first crutch ofthe pair of crutches shown in FIG. 1 during a patient step;

FIG. 15B is a line graph depicting the dynamic load on a second crutchof the pair of crutches shown in FIG. 1 during the same patient step;

FIG. 16 is a line graph depicting the dynamic load on the pair ofcrutches shown in FIG. 1 collectively during the patient step;

FIG. 17 depicts another GUI displayed by the mobile patient softwareapplication at the patient mobile device of FIG. 1 ;

FIG. 18 depicts a GUI displayed by a web-based doctor softwareapplication at the doctor mobile device of FIG. 1 ;

FIG. 19 is an elevation view of an alternative embodiment of the smartcrutch tip electronic device that is integrally formed with a crutch;

FIG. 20 is a cross-section of the smart crutch tip electronic device ofFIG. 19 taken along line 20-20;

FIG. 21 is an exploded view of the smart crutch tip device of FIG. 19 ;

FIG. 22 is a schematic diagram of an alternative embodiment system forpromoting proper use of a during lower extremity rehabilitation;

FIG. 23 is a front elevation view of one of the smart crutch tipelectronic devices of FIG. 22 ;

FIG. 24 is a side elevation view of the smart crutch tip electronicdevice of FIG. 23 ;

FIG. 25 is an exploded view of the smart crutch tip electronic device ofFIG. 23 ; and

FIG. 26 shows a user interface for configuring the smart crutch tipelectronic device of FIG. 23 .

DETAILED DESCRIPTION

In this document, the term “exemplary” should be understood to mean “anexample of” and not necessarily to mean that the example is preferableor optimal in some way. Terms such as “upper”, “lower”, and “above” maybe used to describe some embodiments in this description but should notbe understood to necessarily connote an orientation of the embodimentsduring manufacture or use.

FIG. 1 is a schematic diagram of an exemplary system 100 for promotingproper use of a walking aid 110 by a patient 112 during lower extremityrehabilitation. In this example, the walking aid 110 is a pair ofcrutches 110R, 110L (generically or collectively crutch(es) 110), andthe lower extremity is an injured left leg. Alternative embodiments ofthe system may be used with other types of walking aids and for othertypes of lower extremity injuries.

The depicted example system 100 has various components, including: twosmart crutch tip devices 120L and 120R (generically or collectivelysmart crutch tip device(s) 120), which have been installed onto crutches110L and 110R (generically or collectively crutch(es) 110) respectivelyin a manner that will be described; a mobile device 130, used by thepatient 112, executing a mobile patient software application (“app”)132; a mobile device 140, used by a doctor 116, executing a mobiledoctor app 142; a computer 150, also used by the doctor 116, executing aweb-based doctor app 152; and a cloud-based server 160 executing abackend server application 162.

Each of the smart crutch tips 120 is an electronic device that isattachable to a respective one of crutches 110 to dynamically measurethe load placed on the crutch 110 as it is being used by the patient112. The smart crutch tips 120R, 120L are designed to intercommunicatewirelessly in order to amalgamate dynamic load information from the twocrutches at one of the smart crutch tips 120R, referred to as the“primary” smart crutch tip. This is done to permit a collective (total)load on the pair of crutches 110 to be computed in real time for eachstep taken using the crutches, as will be described below.

In overview, the smart crutch tips 120 are designed to promote patientcompliance with a lower extremity rehabilitation program that has beenprepared specifically for the patient 112 by the doctor 116. The smartcrutch tips 120 do this by receiving and utilizing patient-specificrehabilitation program data 144 based on rehabilitation programparameters originating from the doctor 116. The data 144 specifies aduration of the rehabilitation program (the “rehabilitation period”)during which the patient should use the crutches 110, e.g., expressed asa number of days, and specifies (indirectly) a weight-bearing target onthe injured lower extremity for each day of the rehabilitation program.

Upon receipt of the rehabilitation program data 144, the smart crutchtips 120 configure themselves to monitor for patient compliance with thedaily weight-bearing target as the crutches are used. More specifically,the smart crutch tips 120 use the current date and time to determinewhich day of the rehabilitation program is currently operative. Thesmart crutch tips 120 then indirectly determine the weight being placedon the injured lower extremity during each step by measuring how much ofthe patient's weight is being carried by the crutches 110. That load iscompared to the target load for the crutches for the current day.

Based on the results of the comparison, feedback is provided to thepatient 112, in real time, in the form of one or more configurable usernotifications, e.g., visual indicators, auditory indicators, or voiceindicators. The user notification(s) indicate(s) whether the weightplaced on the injured lower extremity is too high or too low. Absence ofa user notification may indicate compliance with the target load, whichmay include being within a range of tolerance of the target. Usage datamay also be continuously or periodically wirelessly communicated to thepatient mobile device 130 and relayed to the cloud-based server 160 fornear real-time access by the doctor 116 in monitoring for patientcompliance with the rehabilitation program from a remote location.

By way of the foregoing mechanisms, the smart crutch tips 120 areoperable to automatically adjust the weight-bearing targets for theinjured lower extremity (i.e., a currently operative target load on thewalking aid) over time in accordance with the rehabilitation programschedule originally prescribed by the doctor 116 for the patient 112.Moreover, the smart crutch tips 120 can automatically adapt themselvesto monitor for compliance with dynamically changeable weight bearingtargets during the rehabilitation period.

It should be appreciated that the smart crutch tips 120 do not directlymeasure the amount of weight placed on the injured lower extremity.Rather, the smart crutch tips 120 compute a peak weight on the pair ofcrutches 110 at a point in the patient's gait at which the patient'sweight will simultaneously be on the crutches and on the injured lowerextremity. The smart crutch tips 120 operate on the presumption that, atthat moment of the patient's gait, whatever portion of the patient'sweight is not on the crutches will be on the injured lower extremity.This is perhaps best understood with reference to FIG. 2 .

FIG. 2 schematically depicts the gait of a patient having an injuredleft lower extremity (e.g., left leg) and an uninjured right leg,walking with the assistance a pair of crutches. Time is representing onthe horizontal axis. Three steps of the patient's gait are depicted inFIG. 2 .

In a first step (step 1) taken between time t0 and time t1, the patientplaces 100% of his or her weight on the uninjured right leg RL. Duringstep 1, neither the tips of the crutches nor the injured leg is on theground. Rather, the crutch tips are being swung forwardly inanticipation of step 2, and the injured leg is suspended.

In a second step (step 2) taken between time t1 and t2, the patientplants two crutch tips on the ground at points CT1 and CT2 respectively.At approximately the same time as the crutch tips are planted, thepatient steps lightly on the injured left leg LL while using thecrutches to steady himself or herself. At this time, the uninjured legRL is swinging forwardly in anticipation of step 3, i.e., is not on theground. As a result, part of the patient's weight will be on the injuredleg, and the remainder of the patient's weight will be on the crutchesat this time. It is at this moment that the weight on the injured legcan be deduced (indirectly measured) by measuring the weight on the pairof crutches and subtracting it from the patient's body weight. This isthe principle by which the smart crutch tips 120 operate to indirectlymeasure the weight placed on the injured leg.

The third patient step (step 3), taken between time t2 and t3, is arepetition of step 1. The cycle is thereafter repeated with step 4 (notdepicted) being a repetition of step 2, and so on. As will beappreciated, the measuring of the body weight on the crutches is onlyperformed during alternate steps—in this example, step 2, step 4, and soforth.

An example embodiment of a smart crutch tip 120 is illustrated in FIGS.3, 4, 5, and 6 in perspective view, elevation view, cross-sectional view(taken along line 5-5 of FIG. 4 ), and exploded view, respectively. FIG.7 is a schematic diagram depicting a simplified representation of alower portion of the smart crutch tip 120 in cross-section when attachedto a crutch leg.

As illustrated in FIGS. 3-6 , the smart crutch tip 120 has a housing 202that houses and protects structural and electronic components of thesmart crutch tip 120. In the depicted embodiment, the housing has twohalves to facilitate device assembly. The first half is an upper housingportion 204, which is substantially cylindrical in the presentembodiment. The second half is a lower housing portion 206, which isgenerally funnel-shaped in the present embodiment. The housing 202 mayhave different shapes and/or different components in alternativeembodiments.

The structural components of the smart crutch tip 120 include a body208, only partly visible in FIGS. 3 and 4 . The body 208 may beconsidered as the primary structural component or frame of the smartcrutch tip 120. It may be made from a rigid, strong, lightweightmaterial, such as aluminum or suitable plastic for example.

As perhaps best seen in FIGS. 5 and 6 , the body 208 defines receptacle210 for receiving the tip of a leg of a walking aid, such as a crutchtip (i.e., the tip of a leg of the crutch), from above. A nut 212 and aresilient split ring 214 at the open end of the receptacle collectivelyserve as a retaining mechanism (or clamp or attachment means) forretaining the tip of the leg of the walking aid within the receptacle210, i.e., for attaching the smart crutch tip 120 to the walking aidwithout tools, as will be described.

Referring to FIGS. 5 and 6 , the body 208 of the present embodiment hasa generally spool-like shape, with upper and lower annular flanges 216,218 depending radially from either end of a central barrel portion 220.In the present embodiment, the barrel portion 220 is generallycylindrical, and the receptacle 210, which is also cylindrical in thisembodiment, is coaxial with the barrel 220. The two flanges 216, 218cooperate with the barrel 220 and the housing 202 to define an enclosedannular space 222 for safely housing electronic components, such asprocessor 252 (see, e.g., FIG. 5 ).

The body 208 includes an annular skirt 224 depending axially from aperiphery of the lower annular flange 218, away from the barrel portion220. The skirt 224 defines a hollow space 226 with an open end (see,e.g., FIG. 5 ). The hollow space 226 accommodates a load sensor 230,whose edges are anchored to the body 208 at skirt 224.

In the present embodiment, the load sensor 230 is an aggregation ofthree load sensor elements 232 held together with fastener 234 (e.g., ascrew). The reason for aggregating multiple sensors 232 may be toaggregate a load-sensing capacity of multiple ones of the load sensorelements. Alternative embodiments may employ other load sensorarrangements, e.g., a single load sensor whose load-sensing capacity issufficient for the purposes described herein.

A screw in the base of the receptacle 210 serves as an adjustable stop236 to guard against possible load sensor damage that may result fromexcessive flexing of load sensor 230. The position of stop 236 may beadjusted by turning the screw to increase or decrease the size of a gap237 above the load sensor 230 within which flexing can occur (see FIG. 6).

The funnel-shaped lower housing portion 206 has a tubular neck 207. Thetubular neck slidably receives a base 240 having a rubber foot 241 atits lower end. The base 240, which is a cylindrical post in the presentembodiment, is configured for limited axial movement (translation) withrespect to the body 208 of the smart crutch tip 120 (vertically in FIG.6 ).

A base stop 244 limits downward movement of the base 240 relative to thebody 208 of the smart crutch tip 120. In the present embodiment, thebase stop 244 is a cuboid rigid element that is attached to the base 240using a bolt 239. More specifically, the base stop 244 is receivedwithin a notch 245 at the upper end 242 of the base 240, and a bolt 239is passed through a central bore 243 of the base stop 244 and threadedinto a vertical bore at the base of the notch 245. In the illustratedembodiment, the base stop 244 has a horizontal extent wider than that ofthe base 240, with the overhanging ends serving to limit downwardmovement of base 240 relative to body 208. The base stop 244 and bolt239 may each be considered as an extension of the base 240 in thisembodiment. Other forms of base stop could be used in alternativeembodiments.

The load sensor 230 is disposed between the body 208 and the bolt 239(and thus base 240, of which bolt 239 may be considered as a part). Assuch, the load sensor 230 is in the load path of the smart crutch tip120. Specifically, in this embodiment, load passes between head offastener 234 and the abutting head of bolt 239.

FIG. 7 is a schematic diagram illustrating a simplified model of aportion of the smart crutch tip 120. FIG. 7 may facilitate comprehensionof the way in which smart crutch tip 120 can be used to measure a loadupon a crutch 110, or other walking aid. For simplicity, FIG. 7 omitscertain components of the smart crutch tip 120, such as the housing 202.Moreover, the components that are depicted are in simplified schematicform. For example, the base 240 and base stop 244 are depictedcollectively as a single combined base element 240, again forsimplicity.

Referring to FIG. 7 , the tip (of the leg) of crutch 110 is receivedwithin the receptacle 210 and is retained therein by the nut 212 and thesplit ring 214 (not shown). When a patient applies weight W to thecrutch 110, a downward force proportional to the applied weight W istransferred to the body 208 of the smart crutch tip 120. This downwardforce causes the body 208 to translate downwardly relative to the base240 in respect of which the body 208 is axially translatable. The edgesof load sensor 230, which are anchored to the body 208 within the hollowspace 226, move with the body 208. A central area of the load sensor 230transfers the downward force to an upper end of the base 240. However,the base 240 is prevented from moving downwardly by the ground G uponwhich the foot 241 sits. A resultant upward force F from the ground G isrelayed by the base 240 (in this example, through bolt 239 see FIG. 6 )and bears upon the central area of the load sensor 230 (in this example,upon fastener 234), causing the load sensor 230 to flex. The flexingcauses the load sensor 230 to output a signal (data) indicative of theamount of weight W that is being borne by the crutch 110.

Referring again to FIGS. 5 and 6 , the smart crutch tip 120 furtherincludes a printed circuit board 250 with a processor 252communicatively coupled to each of a memory 254 and a short-rangewireless transceiver 256 (e.g., Bluetooth™ transceiver). The processor,memory, and transceiver may for example comprise a Bluetooth™ 5 moduleor Bluetooth™ BLE module, which may be a single integrated circuitcomponent. The electronic components are powered by batteries 258 heldby a battery holder 260, which also supports the printed circuit board250 in this embodiment.

The memory 254 includes processor-executable instructions, e.g.,firmware, that govern operation of the smart crutch tip 120 as describedherein. The instructions may for example be loaded during manufacture ofthe smart crutch tip 120 and may be subsequently updated, e.g., viaflashing.

The smart crutch tip 120 also includes an auditory notification element262 (e.g., a buzzer), a visual notification element 264 (e.g., an LEDprotected by a transparent cover 266), and a speaker for providing voicenotifications (not expressly depicted). These elements are for providinguser feedback regarding target compliance directly from the smart crutchtip device itself. The mobile patient app 132 may also be configured toprovide similar user notifications when in wireless communication range(e.g., Bluetooth™ LE range) of the smart crutch tip 120. If the body 208is made from an electrically conductive material (e.g., aluminum), thena sheet of insulation 268 may be wrapped around the surface of barrel220 to electrically isolate the printed circuit board 250, and otherelectrical components, from the body 208. Insulation 268 may beunnecessary when the body 208 is made from an electricallynon-conductive material.

Referring again to FIG. 1 , the crutches 110 may be one of a variety oftypes of crutches, such as axillary (underarm) crutches, elbow(lofstrand or Canadian) crutches, gutter (forearm support) crutches, orotherwise. Each crutch has a leg whose length may be adjustable toaccommodate patients of different heights.

The mobile devices 130 and 140 (FIG. 1 ) may for example be smartphonescarried by the patient 112 and the doctor 116 respectively, each havinga touchscreen display for example. The computer 150 may for example be alaptop computer, desktop computer, or tablet used by the doctor 116.

The mobile doctor app 142 (FIG. 1 ) provides a mechanism for the doctor116 to customize, prescribe, and optionally update lower extremityrehabilitation programs for one or more patients from the convenience ofhis mobile device 140. The mobile doctor app 142 also permits the doctor116 to monitor the progress of a patient to whom a rehabilitationprogram has been prescribed. Monitoring can be performed in real timewhile the crutches 110 are being used. As will be described, monitoringis facilitated by graphical user interfaces (GUIs) by which the mobiledoctor app 142 may efficiently display data regarding patient compliancewith a prescribed rehabilitation program. The doctor web app 152provides functionality like that of the mobile doctor app 142 but isweb-based and thus platform-agnostic.

The mobile patient app 132 (FIG. 1 ) provides a mechanism for thepatient 112 to receive a rehabilitation program designed by doctor 116and to configure the smart crutch tips 120 to implement thatrehabilitation program in the manner described herein. The mobilepatient app 132 also receives usage data from the smart crutch tips 120,in real-time, indicating whether the crutches 110 are being used inaccordance with the rehabilitation program. The patient 112 canefficiently display usage data in various ways using GUIs in the mobilepatient app 132, as will be described. The usage data is alsocommunicated back to the doctor 116 by way of the backend serverapplication 162 for display within the mobile doctor app 142 and/orweb-based doctor app 152, described above.

Operation of the system 100 will be described in the context of anexample usage scenario. In this scenario, the patient 112 is a male whohas suffered a lower extremity injury and has undergone surgery as aresult. It presumed that the patient 112 has been referred to the doctor116 for post-surgical rehabilitation. For example, the referral may bemade verbally or in writing by a surgeon who performed the surgery. Byway of the referral, the doctor 116 may be provided with unique patientcontact information, such as a mobile telephone number or email address,and informed of the nature of the patient's lower extremity injury.

To prepare a rehabilitation program for the patient 112, the doctor 116may invoke the mobile doctor app 142 on his mobile device 140. The app142 may have been downloaded to the doctor's mobile device 140 from anapp store, such as Google™ Play or the Apple™ App Store for example. Thedoctor may have completed a registration procedure upon initial appinvocation, e.g., specifying information that may include the doctor'sname, location, professional specialization, experience, workplace, andtelephone number.

If the patient 112 is a new patient, the doctor 116 may initially usethe app 142 to create a new patient record. A patient record, which maybe referred to as a “patient card”, may be considered as a digitalrepresentation of a patient file maintained in the context of a lowerextremity rehabilitation. The mobile doctor app 142 may permit the userto create multiple patient records to permit the user to oversee therehabilitation of multiple patients in parallel.

Creation of a new patient card may entail three steps.

In a first step, the app 142 may prompts the doctor 116 to enter uniquepatient contact information for patient 112, such as a mobile telephonenumber or an email address.

In a second step, the app 142 may prompt the doctor 116 to specify thetype of lower extremity injury that has been suffered. For example, theapp 142 may display GUI that includes a radio button (or other userinput mechanism) with two mutually exclusive options: a “surgery” optionand a “therapy” option. For the present scenario, the surgery option maybe chosen to indicate that the patient 112 has undergone surgery. Thetherapy option may be chosen in scenarios in which a lower extremityinjury has been suffered but no surgery has been performed.

The GUI may further prompt the doctor to enter specifics regarding theinjury, e.g., via several pull-down lists (or other user inputmechanism). One pull-down list may be used to identify the lowerextremity that has been injured, which in this example is the left hipjoint. Another pull-down list, which may appear only in the case wherethe surgery option was chosen, may specify the type of surgery that wasperformed (e.g., metal osteosynthesis in this example). A furtherpull-down list may be used to precisely identify the injury that wasinitially suffered (e.g., a fracture of the femoral neck in thisexample).

In a third step, the doctor app 142 may prompt the doctor 116 to specifyand/or customize the parameters of a rehabilitation program. To thatend, the mobile doctor app 142 may display a GUI 300 as shown in FIG. 8. In the depicted embodiment, the GUI 300 permits the rehabilitationprogram to be specified in terms of one, and possibly multiple,rehabilitation phases. For each phase, the doctor 116 is prompted tospecify the following parameters: the type of loading that should beperformed on the injured lower extremity during that phase (zero load,constant load, or steadily increasing load); the duration of the phase;and the percentage of body weight to apply to the injured lowerextremity during that phase. Each phase that is specified by the user isrepresented as a numbered entry in GUI 300. In alternative embodiments,other GUI formats could be used.

In the example GUI 300 depicted in FIG. 8 , the doctor 116 has specifieda six-week rehabilitation program having three phases. A first numberedentry 302 displayed in GUI 300 represents a first, “non load” (i.e., 0%loading) phase, whose duration has been set to two weeks. A secondnumbered entry 304 represents a second, constant load phase, also havinga duration of two weeks, during which 30% body weight should be appliedto the injured lower extremity. A third numbered entry 306 represents athird, increasing load phase, also having a duration of two weeks,during which the body weight applied to the injured lower extremityshould increase progressively from 30% to 70%. In GUI 300, the numericalorder of the entries, i.e., their relative ordinal positions, specifiesthe chronological order in which the phases should be performed duringthe rehabilitation program.

In the example GUI 300 of FIG. 8 , the “+” (plus) icon 308 and “−”(minus) icon 310 depicted in each entry are user input mechanisms whoseselection either increases or decreases, respectively, a duration (here,in weeks) of the phase that is represented by the entry in associationwith which the icons are displayed. A phase may be eliminated by settingits duration to zero weeks. Moreover, the doctor 116 may use the “edit”icons 312 to change the percentage of loading, e.g., in increments of10%, for the phase represented by the entry in which the icons aredisplayed. Notably, the degree of loading is expressed in relativeterms, e.g., as a percentage (fraction) of total body weight, ratherthan in absolute units such as pounds, since the doctor 116 may not haveany indication of the patient's weight at this stage.

Once the rehabilitation program has been customized as the doctor 116sees fit, selection of the “send the program to the patient” button 336(or similar GUI construct) may cause two steps to be performed.

Firstly, data 143 indicative of the specified rehabilitation programparameters may be communicated to the backend server application 162along with a unique patient identifier, e.g., the unique patient contactinformation (see FIG. 1 ). The backend server application 162 may createa patient database record (not expressly depicted) containing thisrehabilitation program parameter data 143, indexable by the uniquepatient identifier. This step may occur transparently from theperspective of the doctor 112. The data 143 in this example includes,for each of a plurality of time intervals (here, days) spanning arehabilitation period (here, six weeks), a target relative load on aninjured lower extremity during the time interval (here, expressed as apercentage) relative to a patient body weight.

Secondly, the earlier-specified patient contact information may be usedto send a communication to the patient 112, e.g., via SMS (text message)or email, to advise that a rehabilitation program has been prepared forthat patient. The communication may include a URL (link) whose selectionby patient 112 may trigger a download of the mobile patient app 132 tothe mobile device 130.

Upon being installed and invoked at the mobile device 130, the mobilepatient app 132 may prompt the patient 112 to complete patientregistration by entering data including name, gender, date of birth, andweight information. It will be appreciated that entry of an indicationof patient body weight is required to permit the mobile patient app 132to convert the relative (percentage) lower extremity target loadsspecified by doctor 116 within the rehabilitation program parameter data143 to absolute target loads (e.g., in pounds or kilograms) that thesmart crutch tips 120 will be capable of measuring, as will bedescribed.

At the completion of patient registration, the mobile patient app 132may communicate the collected patient information to the backend serverapplication 162. The backend server application 162 may add thatinformation to the patient database record maintained at the cloud-basedserver 160.

Based on the presence of rehabilitation program parameter data 143 inthe patient database record, the mobile patient app 132 may notify thepatient 112 that a rehabilitation program has been prepared by thedoctor 116. Upon receiving approval from the patient 112, therehabilitation program parameter data may 143 be communicated to themobile device 130 for use by the mobile patient app 132.

At this stage, the patient 112 may acquire the pair of smart crutch tips120, e.g., from the doctor 116 or another source. The crutches 110 mayalready in the possession of the patient 112 or may be newly acquiredalong with the smart crutch tips 120.

One of the smart crutch tips 120R may then be installed onto the tip ofa leg of the right crutch 110R, and the other smart crutch tip 120L maybe installed onto the tip of a leg of the second crutch 110L.Installation (attachment) may entail removing a rubber foot from eachcrutch leg, inserting the tip of the crutch leg through the nut 212 andinto the receptacle 210 of the respective smart crutch tip 120, andtightening of the nut 212 to attach the body 208 the smart crutch tip120 to the crutch 110. The smart crutch tips 120R, 120L may beconsidered to be associated with the crutches 110R, 110L, respectively,onto which they have been, or will be, installed. Each of the smartcrutch tips 120 may then be activated using a power button (notexpressly depicted).

At this stage, the mobile patient app 132 may display a GUI 350 as shownin FIG. 9 . This GUI 350 may be considered as a main GUI screen of themobile patient app 132 by which the patient 112 can monitor dailyprogress through the rehabilitation program. As illustrated, the mainGUI 350 includes a progress bar 352 showing how much of the lowerextremity rehabilitation program has been completed. In this embodiment,a textual indicator “Day 0/42” indicates that the patient 112 has notyet commenced the six-week (42-day) rehabilitation program. A recentusage history display area 354 may accordingly be blank as shown in FIG.9 .

To establish a wireless connection between the mobile device 130 and thesmart crutch tips 120 by which data may be exchanged, the user may beprompted to select a “Connect” button 356 or similar GUI construct. Inthe present embodiment, selection of this button may trigger aBlueTooth™ LE pairing process between the mobile device 130 and one ofthe smart crutch tips 120R that has been predesignated as the “primary”smart crutch tip that will be responsible for communication with themobile device 130 on behalf of the pair of smart crutch tips 120R, 120L.For example, upon selection of the “connect” button 356, the mobiledevice 130 may scan for any BlueTooth™ LE advertising packets beingwirelessly broadcast by any nearby smart crutch tip devices. In sodoing, the mobile device 130 will detect the proximity of primary smartcrutch tip 120R and may identify that device as being proximate. Uponuser confirmation that connection should proceed, the two devices mayexchange security keys and establish a data communication channel.

In the present embodiment, the mobile device 130 does not communicatedirectly with the other, secondary smart crutch tip 120L. The reason isthat the primary smart crutch tip 120R is solely responsible forcommunicating with the mobile device 130 on behalf of the pair of smartcrutch tips 120 in this embodiment. The secondary smart crutch tip 120Lwill communicate information about the dynamic load upon associated leftcrutch 110L, wirelessly in real time, to the primary smart crutch tip120R. In turn, the primary smart crutch tip 120R will use theinformation from the secondary smart crutch tip 120L, together withlocally measured dynamic load information upon associated right crutch110R, to calculate the collective load on the pair of crutches 110 inreal time, as will be described. It is the collective load informationthat will be communicated to the mobile device 130.

The primary smart crutch tip 120R of the present embodiment is operableto automatically establish a wireless connection with the secondarysmart crutch tip 120L, e.g., soon after the devices 120R, 120L arepowered up. This may be done via a short-range wireless communicationmechanism such as Bluetooth™. In one embodiment, a unique Media AccessControl (MAC) address of the secondary smart crutch tip 120L may bepreprogrammed into the firmware of the primary smart crutch tip 120R,e.g., during manufacture, to facilitate such automatic establishment ofthe wireless connection, transparently from the perspective of the user.

After some predetermined number of steps has been taken (e.g., fivesteps), the rehabilitation program may be considered to have commenced.The current date at the mobile device when this occurs may be deemed asthe first day of the rehabilitation period.

The mobile patient app 132 may use the rehabilitation program parameterdata 143 originating from the doctor 116 and the patient body weightinformation specified locally by the patient 112 to generate and outputrehabilitation program data 144 for configuring the smart crutch tips120. The rehabilitation program data 144 specifies patient-specificabsolute target loads for the pair of crutches 110 for each day of therehabilitation program. In effect, the rehabilitation program data 144defines a schedule for use by the smart crutch tip 120, which specifiesa target (absolute) load for the walking aid for each day of therehabilitation period. A calendar date may be computed and stored witheach of the daily target loads (of which there are 42 in the presentembodiment), to indicate when each target load will be operative.Creation of the array may be triggered by the patient 112 in the mobilepatient app 132. Alternative embodiments could employ other datastructures besides an array (e.g., a linked list of records).

It will be appreciated that expressing the targets as absolute weighttargets for the crutches, rather than as absolute weight targets for theinjured lower extremity, facilitates use of the smart crutch tips 120 tomonitor rehabilitation program compliance by patient 112 in real time.The reason is that the smart crutch tips 120 directly measure the loadon the crutches rather than directly measuring a load on the injuredlower extremity.

In the present embodiment, the rehabilitation program data 144 isexpressed as an array of N elements, where N is a positive integerindicating a number of time intervals into which the rehabilitationperiod has been divided. In the present embodiment, each of the Nelements represents a single day of the rehabilitation program andcontains a value indicating a target load for the pair of crutches forthat day, in absolute units (e.g., pounds or kilograms). The rationalefor using a single day as the time interval is that patients may expectthat their use of the walking aid over the course of a single day shouldbe consistent, i.e., should target the same load throughout the day. Itis possible that the rehabilitation program data 144 in alternativeembodiments could specify target loads for time intervals that areshorter than or longer than one day. In general, the term “timeinterval” as used herein refers to a finite period of time, be it oneday or otherwise.

FIG. 10 depicts example rehabilitation program data 144 that may begenerated by the mobile patient app 132 from the example rehabilitationprogram parameters specified in FIG. 8 . The loads in FIG. 10 assume apatient-specified weight of 200 pounds. As illustrated, the data 144comprises an array of 42 elements. Each element is identified in FIG. 10by a reference numeral that is the ordinal day number of the 42-day (sixweek) rehabilitation program preceded by “144-”. For example, arrayelement 144-3 contains the target load for the pair of crutches 110 forthe third day of the rehabilitation program. The associated calendardate of Jan. 20, 2021 for that day (expressed in format MM/DD/YY in FIG.10 ) may also be stored in the array element 144-3.

It will be appreciated that elements 144-1 to 144-14 of FIG. 10correspond to phase 1 of the rehabilitation program (entry 302 of FIG. 8), elements 144-15 to 144-28 of FIG. 10 correspond to phase 2 of therehabilitation program (entry 304 of FIG. 8 ), and elements 144-29 to144-42 of FIG. 10 correspond to phase 3 of the rehabilitation program(entry 306 of FIG. 8 ). From the perspective of the smart crutch tip120, however, there may be no awareness of the existence of anyphase(s). The reason is that the smart crutch tip 120 does not requirephase information to be able to provide immediate user feedbackregarding target load compliance via visual, auditory, or voicenotifications. In contrast, the mobile patient app 132 does maintainphase information, so that more sophisticated usage analytics may beprovided to the patient 132 on request.

To compute the crutch target loads expressed in pounds for each of the42 elements of array 144, the mobile patient app 132 may first computethe lower extremity target load in pounds for each day. This may be doneby multiplying the target percentage load on the lower extremity, asspecified by the doctor 116 for the relevant day, by the patient weightof 200 pounds. The resultant values may then be subtracted from thepatient weight to calculate daily crutch target loads, i.e., tocalculate, for each of the plurality of time intervals spanning therehabilitation period, a target absolute load on the walking aid duringthe time interval. In this example, the target loads are expressed inpounds, e.g., for consistency with the unit of measure of the loadsensor 230 (which is assumed to be pounds the present example).

It will be appreciated that the progressively decreasing target loadvalues in array elements 144-29 to 144-42 correspond to theprogressively increasing phase 3 lower extremity target load of 30%-70%of body weight. The target load values in the array may be computed asfollows. First, the change in absolute weight on the lower extremityduring this phase may be calculated: (70%-30%)*200 lbs.=80 lbs. Thenthat change in absolute weight may be broken into fixed daily incrementsfor the number of days in the phase (e.g., increments of 6.15 lbs. inthis example). Then the crutch target load for each day of the phase maybe set to the previous day's target load less that amount. In thepresent embodiment, target loads in array 144 are rounded to the nearestpound, although such rounding is not absolutely required.

Once the mobile patient app 132 has generated the rehabilitation programdata 144 (array in this example), the data 44 is wirelessly transmittedto the primary smart crutch tip 120R. As earlier noted, one smart crutchtip 120R is predesignated as the primary and the other smart crutch tip120L is predesignated as the secondary. The primary smart crutch tip120R is responsible not only for measuring the dynamic load on its ownrespective crutch 110R for each detected step but also for combiningthat dynamic load data with the dynamic load data received wirelesslyfrom the other, secondary crutch to compute a peak load for the pair ofcrutches 110. The secondary smart crutch tip 120L is only responsiblefor measuring the dynamic load on its respective crutch 110L for eachpatient step and for wirelessly communicating that information to theprimary. The secondary smart crutch tip 120L does not directlycommunicate with the mobile device 130 in this embodiment. In thisarrangement, the rehabilitation program data 144 is stored only at theprimary smart crutch tip 120R. The smart crutch tips 120R, 120L that aredesignated as primary and secondary may be on either crutch and oneither side of the patient's body.

At this stage, the crutches 110 are ready for use by the patient 112,e.g., as shown in the perspective view of FIG. 11 .

Operation of the smart crutch tips 120 for monitoring compliance with aweight-bearing target of a lower extremity rehabilitation program isdepicted in FIGS. 12-16 . FIG. 12 is a flowchart of operation 400 of theprimary smart crutch tip 120R for monitoring compliance with a currentlyoperative target load during the rehabilitation program. Operation 400may be triggered whenever motion is detected at the smart crutch tip120R, e.g., using an accelerometer (not expressly depicted). FIGS. 13and 14 are flowcharts providing detail regarding certain operations ofFIG. 12 in the case where the walking aid comprises two crutches. Theoperations in FIGS. 12, 13, and 14 may be effected largely or entirelyin software, which may be stored in memory 254 and executed by processor252. The software may for example be firmware. FIG. 15 illustrates thedynamic load data measured by each of smart crutch tip 120R and smartcrutch tip 120L during an example patient step. FIG. 16 illustrates thetotal dynamic load on the pair of crutches 110 during the same patientstep.

For the purpose of FIG. 12 , it is presumed that the primary smartcrutch tip 120R has already received, and has stored in its memory 254(see FIG. 6 ), the array of rehabilitation program data 144 depicted inFIG. 10 . It will be recalled that this data 144 corresponds to thesix-week rehabilitation program customized by the doctor 116 using theGUI 300 of FIG. 8 . The rehabilitation program is presumed to have beencommenced on Jan. 18, 2021. It is also presumed that the clocks of theprocessors 252 on the two smart crutch tips 120R, 120L have beensynchronized. This may for example occur at the time that the wirelessconnection between the smart crutch tips 120R, 120L is firstestablished.

In operation 402 (FIG. 12 ), a currently operative time interval of theat least one time interval of the rehabilitation period is identified.In the present embodiment, identification of the currently operativetime interval is based on the current date. More specifically, theprocessor 252 of the primary smart crutch tip 120R determines thecurrent date. This may for example be done in software via a suitableoperating system API call. Alternatively, the current date may betransmitted by the mobile device 130 to the primary smart crutch tip120R at the time that a wireless connection is established between thetwo devices.

In this example, it is presumed that current date that is determined inoperation 402 is Feb. 2, 2021. Using this information as a lookup intothe array 144 of FIG. 10 , the primary smart crutch tip 120R identifiesthe 16th day of the 42-day rehabilitation period, represented by arrayelement 144-16, as the current day—or, more generally, as the currentlyoperative time interval—of the rehabilitation period. In other words, itis presumed that patient 112 has already been using the smart crutchtips 120 for 15 days. The processor 252 may then read the valuecontained in that array element, i.e., 140 pounds, and may update a“current target load” variable to indicate the target for the currentday.

In operation 404 (FIG. 12 ), data is received from one or more loadsensors indicative of a dynamic load on the walking aid during a patientstep. For the present scenario, in which the walking aid comprisesmultiple units (two crutches 110), operation 404 may entail the stepsshown in FIG. 13 .

Referring to FIG. 13 , in step 410, the primary smart crutch tip 120Rreceives data from load sensor 230 indicative of a dynamic load on thefirst crutch 110R during a patient step. A step may be considered tohave occurred when processor 252 of the primary smart crutch tip 120Rdetects the following pattern output by the load sensor 230: zero loadfollowed by a positive load followed by zero load. For this example, itis assumed that the dynamic load is as depicted in FIG. 15A.

FIG. 15A is a line graph depicting the dynamic load measured by the loadsensor 230 of the primary smart crutch tip 120 during the three patientsteps shown in FIG. 2 . Load is represented by the vertical axis, andtime is represented by the horizontal axis. For step 410, it is presumedthat the processor 252 receives data corresponding to the dynamic loadbetween time t1 and time t2 of FIG. 15A. The data may be sampled at apredetermined frequency to generate a digital representation of the linegraph of FIG. 15A. The digital representation may be recorded withtimestamp information indicating when the samples were taken. As shownin FIG. 15A at 440, the maximum load measured on the first crutch 110Rduring step 2 is 62 pounds.

In step 412 of FIG. 13 , the primary smart crutch tip 120R receiveswireless signals carrying data indicative of a dynamic load on thesecond crutch 110L during the same patient step. The secondary smartcrutch tip 120L may use the same approach as the first crutch todetermine when a patient step has been taken and to sample the load onthe second crutch 110L during the step. The dynamic load on the secondcrutch is presumed to be as shown in FIG. 15B, with a maximum load of 80pounds shown at 442. The samples capturing the dynamic load on thesecond crutch may be transmitted via Bluetooth™ LE to the primary smartcrutch tip 120R along with associated timestamp information indicatingwhen the samples were taken.

It will be appreciated that the maximum load on the second crutch duringthe step, i.e., 80 pounds, is greater than the maximum load on the firstcrutch during that step, i.e., 62 pounds. Such discrepancies in loadbetween crutches may arise, e.g., when the patient 112 leans moreheavily on one crutch than on the other while taking a step.

Referring again to FIG. 12 , in operation 406, the smart crutch tip 120Rdetermines, based upon the received data, a peak load upon the pair ofcrutches 110 collectively during the patient step. For the presentscenario, in which the walking aid comprises two crutches 110, operation406 may entail the steps depicted in FIG. 14 .

In step 420 (FIG. 14 ), first crutch dynamic load data is time-alignedwith the second crutch dynamic load data. This step may entail usingtimestamp information to identify pairs of load samples that were takensubstantially simultaneously at the smart crutch tips 120R, 120L,respectively.

In step 422 (FIG. 14 ), a representation of the dynamic load on the pairof crutches collectively during the patient step is generated. This stepmay entail summing the time-aligned samples from the two smart crutchtips 120R, 120L to generate a representation of total load on bothcrutches 110R, 110L. In the present example, this may result in adigital representation of the line 450 shown in FIG. 16 .

FIG. 16 is a line graph whose axes are analogous to those of FIGS. 15Aand 15B. Dashed lines 452 and 454 represent dynamic load data for crutch1 and crutch 2, respectively, as depicted in FIGS. 15A and 15B,respectively. Line 450 represents a summation of lines 452 and 454,which may be the result of step 422 of FIG. 14 . It will be appreciatedthat the time-aligning is performed so that the summing will accuratelyreflect the total load on the crutches 110 at the relevant times.

In step 424 (FIG. 14 ), the maximum load of the representation (sum)generated in step 422 is determined. Referring to FIG. 16 , the maximumload 456 for the step taken between time t1 and time t2 is determined tobe 142 pounds. This load may be considered as the peak load on the pairof crutches 110R, 110L during the patient step.

Referring again to FIG. 12 , in operation 408, a user notification isprovided indicating whether the peak load upon the walking aid duringthe patient step, as determined in operation 406, is non-compliant withthe target load for the currently operative time interval, i.e., day 16of the six-week rehabilitation program. In the present embodiment, thepatient 112 is considered to have complied with the target load if thepeak load is within a range that is centered on the current target loadand whose limits are 10% greater than and 10% less than the target load.

In the present example, the target load for the current date of Feb. 2,2021, is 140 pounds (see element 144-16 of FIG. 10 ), so the range ofweights that are considered compliant is 126 lbs. to 154 lbs. Becausethe peak load of 142 lbs. determined in operation 406 is within thatrange, no user notification is provided.

Had the peak load from operation 406 been greater than 154 lbs., meaningthat too much weight was on the crutches 110 and not enough weight wason the injured lower extremity, the primary smart crutch tip 120R mayhave provided a visual, auditory, or voice notification to urge thepatient 112 to put more weight on the injured lower extremity.Conversely, if the peak load from operation 406 had been less than 126lbs., meaning that not enough weight was on the crutches 110 and toomuch weight was on the injured lower extremity, the primary smart crutchtip 120R may have provided a visual, auditory, or voice notification tourge the patient 112 to put less weight on the injured lower extremity.

At the conclusion of operation 408 of FIG. 12 , the primary smart crutchtip 120R may store usage data pertaining to the patient step forsubsequent analysis. The stored data may include the time at which thestep was taken and the peak load on the crutches during the step. Insome embodiments, the maximum load on each of the two crutches duringthe step, as show in FIG. 15A at 440 and FIG. 15B at 442, may also bestored. A step counter for the current day (or, more generally, timeinterval) may also be incremented.

Operations 404, 406, and 408 may thereafter be repeated for each steptaken by the patient using the crutches 110. In the result, the primarysmart crutch tip 120R may accumulate usage data for multiple steps takenat various times during the patient's rehabilitation program. This usagedata is periodically wirelessly transmitted back to the mobile patientapp 132, e.g., via Bluetooth™ LE, when connectivity with the mobiledevice 130 is available. In one embodiment, the usage data is sent inreal time immediately after each step is taken.

The mobile patient app 132 may be used to display various types ofanalytics of the patient's usage of the crutches 110 during therehabilitation program. For example, referring to FIG. 17 , the main GUI350 of the mobile patient app 132 may display recent usage data indisplay area 354. In the GUI 350, individual steps are represented asbars in a bar graph whose vertical axis indicates load on the injuredlower extremity (expressed in relative terms, e.g., percent) andhorizontal axis represents time. The currently operative target load forthe injured lower extremity (30% in this example) may be displayed in atextual banner 360 and as a horizontal line 362 in the bar graph. Therange of weights that are considered compliant (in this example, from20% to 40% of body weight) may be indicated, e.g., by highlighting therange using a differently colored graph background 364.

In GUI 300, the bars of the bar graph may be color-coded. Steps withinsufficient load on the injured lower extremity may be denoted by awhite bar 366; steps with an excessive load on the injured lowerextremity may be denoted by a red bar 368; and steps that were compliantwith the operative recommended target load may be denoted by a green bar370. Such color coding, or other types of visual indicators, may providevaluable, at-a-glance user feedback as to whether the crutches 110 arebeing properly used. A step count indicator 372 may provide a tally ofsteps taken during the current day and may provide a progress indicatorshowing progress towards a daily goal, which the doctor may prescribethrough the mobile doctor app 142.

The mobile patient app 132 also relays the recent usage data that itcontinuously or periodically receives from the primary smart crutch tip120R to the cloud-based backend software application 162 for storage inconnection with the database record for patient 112. The stored usagedata information is accessible by the mobile doctor app 142 and/orweb-based doctor app 152.

The doctor 116 may use the doctor app 142 or 152 to remotely monitor, inreal time or near-real time, the patient's usage of the crutches 110during the rehabilitation program. Various types of analytics may beviewable. For example, FIG. 18 illustrates an example GUI 500 of theweb-based doctor app 152. This GUI 500 can be used to display historicalusage data of the patient 112. A similar GUI 500 could be generated anddisplayed at the mobile patient app 132.

The example GUI 500 includes a composite bar graph 502 in which thevertical axis represents step count and the horizontal axis identifiesthe day (or, more generally, a chosen time interval) of therehabilitation period. Each bar represents steps taken using thecrutches 110 in a single day. The height of the bar represents totalsteps taken during the relevant day. The component bar portions makingup each bar collectively indicate the proportion of the steps takenduring that day in which the load on the injured lower extremity was toohigh, too low, or in the recommended range.

For example, bar 504 represents steps taken on Feb. 2, 2021. The heightof the bar 504 indicates that 350 steps were taken using the crutches110 on that day. A first bar portion 506 shows that, for 20 of thosesteps, the load on the injured lower extremity was excessive. A secondbar portion 508 shows that, for 300 of those steps, the load on theinjured lower extremity was in the recommended range, i.e., compliantwith the target load. A third bar portion 510 shows that, for 30 ofthose steps, the load on the injured lower extremity was insufficient.

A pie chart icon 512, or similar GUI construct, may be used to presentan at-a-glance graphical indicator of the proportion of excessivelyloaded, insufficiently loaded, or compliant steps taken by the patient112 during a chosen duration of the rehabilitation period (e.g., day,week, month, or total rehabilitation period). Another icon 514 may beused to present an at-a-glance graphical indicator of a proportion ofweight being loaded onto the left crutch 110L versus the right crutch110R, on average, for a chosen duration. The GUI may further display thetotal time spent walking using the crutches 110 for the currentlydisplayed interval, such as a week.

The doctor can also make changes to the weight-bearing rehabilitationprogram if necessary. Any such changes are communicated to the patientapp and are relayed to the smart crutch tip devices. This may result inan update to the rehabilitation program data 144 array elementscorresponding to the current day and any days remaining in therehabilitation period.

As will be appreciated, the described system 100 provides a flexible andconvenient mechanism for a patient 112 and a doctor 116 to monitor forpatient compliance with a prescribed lower extremity rehabilitationprogram, even when the target load dynamically changes. After beingconfigured once at the outset of a rehabilitation period, the smartcrutch tips 120 can change the target load autonomously andautomatically during the rehabilitation period, in accordance with therehabilitation program. The smart crutch tips 120 can also monitor forcompliance with the dynamically changing target load throughout therehabilitation program. The likelihood of patient compliance with therehabilitation program may be improved in comparison to conventionaltechniques.

As described above, the smart crutch tip 120 has attachment means (nut212 and resilient split ring 214) for selectively attaching the smartcrutch tip 120 to various types of walking aids. The ability to attachthe device 120 to different walking aids may be considered advantageousbecause the same device can be used for rehabilitation from differenttypes of lower extremity injuries.

Nevertheless, the attachment means may contribute to device complexity,weight, and production cost. Moreover, attachment of the smart crutchtip 120 to a walking aid may increase the height of the walking aid byperhaps 8 to 12 centimeters in some embodiments, which may make thewalking aid too tall for a patient to use properly. For this reason, itmay be necessary to reduce the height of the walking aid by acomplementary amount, e.g., by collapsing a telescoping leg portion ofthe walking aid, when the smart crutch tip 120 is attached. Somepatients may consider attaching the smart crutch tip 120 and adjustingthe walking aid height to be tedious. Moreover, some patients mayconsider the added weight and/or girth of the smart crutch tip 120device(s) to feel awkward, at least initially, as compared with usingthe walking aid by itself.

For such patients, a different embodiment of electronic device, which issimilar to smart crutch tip 120 in terms of functionality but lighterand integrally formed with, or embedded within, the walking aid, may bepreferred. One such example embedded smart crutch tip device is depictedin FIGS. 19, 20, and 21 .

FIG. 19 is an elevation view of an axillary crutch 610 (a form ofwalking aid) having a smart crutch tip 620 integrally formed therewith.The smart crutch tip 620 is an electronic device whose functionality islike that of smart crutch tip 120. The form factor of the crutch 610depicted in FIG. 19 is such that, from outward appearances, the presenceof an embedded smart crutch tip 620 is not immediately apparent. This isnot strictly required but may facilitate patient acceptance of smartcrutch tip technology.

The electronics of smart crutch tip 620 are arranged to fit within thebody or structure of the walking aid. In the depicted embodiment, thesmart crutch tip 620 is designed to fit within a tubular leg portion 611of the crutch 610. The crutch leg 611 (or, more generally, walking aidbody) acts as the housing for the smart crutch tip 620, reducing oreliminating the need for a dedicated housing, such as housing 202 ofsmart crutch tip 120 (see, e.g., FIG. 5 ). This may help to reduce aweight and/or bulkiness of the smart cane tip 620.

FIG. 20 is a cross-section of the embedded smart crutch tip 620 takenalong line 20-20 of FIG. 19 . FIG. 21 is an exploded view of the smartcrutch tip 120 with some components (e.g., fasteners) omitted and othercomponents (e.g., circuitry) depicted schematically for clarity.

Referring to FIGS. 20 and 21 , it should be appreciated that manycomponents of the smart cane tip 620 are analogous to counterpartcomponents in smart crutch tip 120 of FIGS. 5 and 6 . These componentsinclude the processor 752, memory 754, and short-range wirelesstransceiver 756 (e.g., Bluetooth™ transceiver), which may be analogousto processor 252, memory 254, and transceiver 256 described above, andmay all form part of a Bluetooth™ 5 module or Bluetooth™ BLE module. Theauditory notification element 762 is also analogous to auditorynotification element 262, shown above.

In the present embodiment, the above-referenced electronic componentsare mounted to a surface of a printed circuit board 750 having anelongate shape designed to fit inside the hollow crutch leg 611. Abattery 758 for powering the smart crutch tip 120 electronics may have asemi-cylindrical shape (see, e.g., FIG. 21 ) to maximize utilization ofspace between the opposite side of the printed circuit board 750 and thewall of crutch leg 611.

The example smart crutch tip 620 has a generally tubular body 708, fixedwith respect to the crutch leg 611, that acts as a primary structuralelement for the device. The body 708 of this embodiment is differentlyshaped from body 208 described above. In particular, the body 708 has ashallow top receptacle 709 with an open top and a deeper bottomreceptacle 726 with an open bottom. The top receptacle 709 supports theprinted circuit board 750 and battery 758. The deepest (uppermost inFIGS. 20 and 21 ) portion of the bottom receptacle 726 accommodates aload sensor 730.

A tubular flanged collar 727 fits snugly within the bottom receptacle726, below the load sensor 730. The collar 727 has a cylindrical centralopening that is sized to slidably receive a crutch tip base 740. Thebase 740, which is a cylindrical post in the present embodiment, isconfigured for limited axial movement (translation) with respect to thecollar 727 and body 708 of the smart crutch tip 120 (vertically in FIGS.20 and 21 ). The base 740 has a rubber foot 741 at its lower end.

As perhaps best seen in FIG. 20 , the smart crutch tip 620 includes abase stop 744 that limits downward movement of the base 740 relative tothe body 708 of the smart crutch tip 620. As with the base stop 244 ofthe earlier-described embodiment, the base stop 744 of the presentembodiment is a cuboid rigid element held within a notch 745 at theupper end of the base 740 by a bolt 739. Other forms of base stop couldbe used in alternative embodiments.

The load sensor 730 is disposed between the body 708 and the bolt 739(and thus base 740, of which bolt 739 may be considered as a part). Assuch, the load sensor 730 is in the load path of the smart crutch tip620.

Configuration and operation of the smart crutch tip 620 may be performedas described above for smart crutch tip 120 and as shown in FIGS. 8-14,15A, 15B, and 16-18 , with certain exceptions. Once such exception isthat the patient 112 need not attach any device(s) to his or her walkingaid, since the smart crutch tip 620 is already integral therewith.Another exception is that user notifications directly from the smartcrutch tip 620 may be limited to auditory user notifications rather thanvisual ones, because the illustrated embodiment lacks a visual usernotification indicator (although one could be provided in alternativeembedded crutch tip embodiments). Otherwise, operation of the mobilepatient app 132, the mobile doctor app 142, and the web-based doctor app152 may be the same as the operation of these apps that was describedabove for removable smart crutch tips 120.

As with smart crutch tips 120R and 120L, in cases when a pair of smartcrutch tips 620R, 620L are used as a pair, one of the smart crutch tips620R is predesignated as the primary device, and the other smart crutchtip 620L is predesignated as the secondary device. Intercommunicationbetween the primary and secondary smart crutch tips 620R and 620L mayoccur as described above for devices 120R and 120L. Each smart crutchtip 620R, 620L may be considered to be associated with the crutches110R, 110L, respectively, with which they are integrally formed.

FIG. 22 illustrates an example alternative system 800 for encouragingproper use of a walking aid (e.g., a pair of crutches 110) during lowerextremity injury rehabilitation. Like system 100, described above,system 800 includes a pair of smart crutch tips 820R, 820L (genericallyor collectively smart crutch tip(s) 820). Each of the smart crutch tips820 is an electronic device that is similar in many respects to smartcrutch tip 120. For example, each smart crutch tip 820 is attachable toa respective one of crutches 110 to dynamically measure the load placedon the crutch 110 as it is being used. Moreover, the smart crutch tips820R, 820L are designed to intercommunicate wirelessly to amalgamatedynamic load information from the two crutches 110, as described abovein connection with FIG. 14 for crutch tips 120R, 120L.

Yet, each smart crutch tip 820 differs from the smart crutch tip 120 incertain respects. A key difference is that the smart crutch tip 820incorporates a display component and user input mechanism (UIM) notpresent in smart crutch tip 120. The display and UIM are usable by thepatient 112, as will be described, to manually program the deviceconsistently with a rehabilitation program from a doctor 116. Anotherdifference is that, for simplicity, smart crutch tip 820 does not store,or relay to any other device, historical usage data showing how thewalking aid has been used during the current rehabilitation period(e.g., as graphically represented in GUI 500 of FIG. 18 for example).Rather, smart crutch tip 820 is limited to providing immediate feedbackto the patient 112, in real time, in the form of one or more usernotifications, e.g., visual indicators, auditory indicators, or voiceindicators. These user notifications may be similar to those provided bysmart crutch tip 120, e.g., notifying the patient 112 whenever theweight applied to the walking aid is excessive or insufficient.

These differences between smart crutch tip 820 and smart crutch tip 120permit the system 800 to be greatly simplified in comparison to system100 of FIG. 1 . For example, the example system 800 omits the followingcomponents of system 100 (see FIG. 1 ): the mobile patient app 132executed at a patient mobile device 130; the mobile doctor app 142and/or web-based doctor app 152 being executed at a doctor mobile device140 and computer 150, respectively; and backend server application 162executed at the cloud-based server 160. The cost of implementing andmaintaining the system 800 may accordingly be reduced compared to system100.

System 800 may be considered particularly suitable for patientrehabilitation in certain patient and/or doctor scenarios, e.g.: whenthe doctor 116 lacks access to, or is unwilling to use, the mobiledoctor app 142 or web-based doctor app 152; when the patient 112 lacks asuitable mobile device for executing the mobile patient app 132; whenthe patient 112 is in a remote location with no internet connectivity,which may prevent the patient-specific rehabilitation program parameterdata 143 originating from doctor app 142 or 152 from being transmittedto a mobile patient app 132 and being converted to patient-specificrehabilitation program data 144 and wirelessly transmitted to smartcrutch tip 120; when the patient 112 prefers to have manual control overrehabilitation program parameters; or a combination of these factors.

A possible trade-off of using system 800 rather than system 100 may be agreater responsibility upon the patient 122 for correctly setting his orher own rehabilitation program parameter settings, including target loadand time interval (duration), as described below. In view of thisresponsibility, system 800 may be best suited for more straightforwardrehabilitation programs, e.g., ones with constant target load settingsover extended periods of time, than for complicated rehabilitationprograms with frequently changing target loads upon the walking aid.

FIGS. 23 and 24 are front and side elevation views, respectively, of anexample embodiment of a smart crutch tip electronic device 820 of system800. FIG. 25 is an exploded view of the smart crutch tip 820 in whichsome components are depicted schematically or are omitted for clarity.

Like smart crutch tip 120, described above, the example smart crutch tip820 has a housing 902 comprised of an upper housing portion 904 and alower housing portion 906, to facilitate device assembly. The housing902 may have different shapes and/or different components in alternativeembodiments.

The smart crutch tip 820 has a receptacle 910 that is sized and shapedfor receiving the tip of a leg of a walking aid, such as a crutch tip,from above. A nut 912 and a resilient split ring 914 (see FIG. 25 ) atthe open end of the receptacle comprise attachment means for selectivelyattaching the smart crutch tip 820 to the walking aid, as describedabove.

The housing portion 904 attaches to a flat body element 908. The twocomponents collectively define a cavity in which the receptacle 910 isformed and electronics are housed. The housed electronics include aprocessor 952, memory 954, and short-range wireless transceiver 956, allcommunicatively coupled with one another and mounted to a printedcircuit board 950. The processor, memory, and transceiver may forexample comprise a Bluetooth™ 5 module or Bluetooth™ BLE module, whichmay be a single integrated circuit. The memory 954 includesprocessor-executable instructions, e.g., firmware, that govern operationof the smart crutch tip 820 as described herein. The instructions mayfor example be loaded during manufacture of the smart crutch tip 820 andmay be subsequently updated, e.g., via flashing. A battery 958 powersthe electronics of smart crutch tip 820 and is rechargeable via acharging port 959.

An auditory notification element 962 (e.g., a buzzer) and a visualnotification element 964 (e.g., an LED) are also mounted to the printedcircuit board 950 and are controllable by the processor 252. Atransparent cover 966 protects the visual notification element 964.

As alluded to above, the smart crutch tip 820 further includes a display970 and user input mechanism 972. The display may for example by aliquid-crystal display (LCD) screen. In the present embodiment, the UIM972 comprises four physical buttons 972R, 972L, 972T, and 972B. Thedisplay 970 and UIM 972 may be mounted to the upper housing portion 904,e.g., by surface mounting or in corresponding openings that are sizedand shaped to receive these components, and are communicatively coupledto processor 952.

The lower housing portion 906 has a central opening 907 that slidablyreceives a cylindrical post or base 940 with a rubber foot 941 at itslower end. A base stop 944, similar to base stops 244 and 744 describedabove, limits downward axial translation of the base 940 relative to thebody 908 and housing 902 of the smart crutch tip 820. The base stop 944fits within a notch 945 at the upper end of base 940 and is attached tobase 940, e.g., using a bolt 939.

A load sensor 930 is disposed between the body portion 908 and the bolt939 (and thus base 740, of which bolt 739 may be considered as a part).As such, the load sensor 930 is in the load path of the smart crutch tip820.

The smart crutch tips 820R and 820L may be predesignated as primary andsecondary, respectively, as described above for smart crutch tips 120Rand 120L. When the primary smart crutch tip 820R is activated, it mayautomatically establish a wireless connection with the secondary smartcrutch tip 820L. This may be done via a short-range wirelesscommunication mechanism such as Bluetooth™ using a preprogrammed MACaddress, as described above.

Unlike smart crutch tips 120R and 620R, described above, the primarysmart crutch tip 820R of the present embodiment is not operable towirelessly receive patient-specific rehabilitation program data 144originating from the doctor 116 defining one or more time intervals withtarget load specified for each time interval (e.g., as depicted in FIG.10 ). Rather, smart crutch tip 820R is manually programmable by a user,such as patient 112, to specify rehabilitation program parameters foronly a single time interval at a time. The rehabilitation programparameters 143 may be specified by a doctor 166, during an in-personvisit or over the phone for example (see FIG. 22 ). The parameters 143may include multiple time intervals with different targets loads fordifferent intervals.

To effect manual programming (configuration) of the smart crutch tip820, firmware stored in memory 954, when executed by processor 952, maycause the display 970 to present three textual fields, as shown in FIG.26 , representing user-configurable rehabilitation program parametersfor a single time interval of a the rehabilitation program. In thisexample, the first field 980 is for specifying the body weight of thepatient, e.g., in pounds. The second field 982 is for specifying thetarget load on the injured lower extremity relative to the body weight,e.g., as a percentage value from 0% to 95%. The third field 984 is forspecifying a duration of a single time interval, e.g., in weeks.

In one embodiment, a user may be able to configure the values in thesefields as follows. User selection of the right button 972R or leftbutton 972L, respectively, of the UIM 972 (see FIG. 25 ) may cause acursor (e.g., reverse video highlighting) to tab forward or backwardthrough the fields 980, 982, and 984. When the cursor highlights aparticular field 980, 982, or 984, user selection of the top button 972Tor bottom button 972B, respectively, may cause the value of that fieldto increase or decrease by some predetermined increment (e.g., in field980, by 5-pound increments). When the values in fields 980, 982, and 984are set as desired, the cursor may be tabbed to either of the “OK” userinput construct 986 or “Cancel” user input construct 988, e.g., usingbuttons 972R or 972L. Then, selection of one of the top button 972T orbottom button 972B may cause any changes made to the values in any offields 980, 982, and 984 to be accepted or rejected.

When the values in the fields 980, 982, and 984 are accepted, theprocessor 952 may automatically compute the target absolute load on thewalking aid for the specified time interval based on the patient weightspecified in FIG. 980 and the target relative load on the injured lowerextremity specified in FIG. 982 . For example, if the patient weightspecified in field 980 is 200 pounds and the target relative load on theinjured lower extremity specified in field 982 is 40%, then the targetabsolute load on the walking aid may be computed by calculating theabsolute load on the injured lower extremity and subtracting thatabsolute load from the body weight, as follows: 200 pounds—(200pounds*40%)=120 pounds.

After some predetermined number of steps has been taken with the walkingaid 110 (e.g., five steps), the time interval of the rehabilitationprogram, as specified in FIG. 984 of FIG. 26 , may be considered to havecommenced. The processor 952 may initiate a countdown timer that hasbeen set to the time interval duration.

Operation 400 of the primary smart crutch tip 820R for monitoringcompliance with the currently operative target load, as computed fromthe values of fields 980 and 982 (see above), is depicted in FIG. 12 .Operation 400 may be triggered whenever motion is detected at the smartcrutch tip 820R, e.g., using an accelerometer (not expressly depicted).

In operation 402, a currently operative time interval of the at leastone time interval of the rehabilitation period is identified. In thepresent embodiment, the currently operative time interval is the onewhose duration was specified in field 984 of FIG. 26 . Operation 402 mayentail verifying that the time interval remains unexpired, e.g., byconfirming that the countdown timer has not yet expired.

In operation 404 (FIG. 12 ), data is received from one or more loadsensors indicative of a dynamic load on the walking aid during a patientstep. For the present scenario, in which the walking aid comprisesmultiple units (two crutches 110), operation 404 may entail the stepsshown in FIG. 13 , as described above.

In operation 406 (FIG. 12 ), the primary smart crutch tip 820Rdetermines, based upon the received data, a peak load upon the pair ofcrutches 110 collectively during the patient step. For the presentscenario, in which the walking aid comprises two crutches 110, operation406 may entail the steps depicted in FIG. 14 , described above.

In operation 408 (FIG. 12 ), a user notification is provided indicatingwhether the peak load upon the walking aid during the patient step, asdetermined in operation 406, is non-compliant with the target load forthe currently operative time interval. In the present embodiment, thepatient 112 is considered to have complied with the target load if thepeak load is within a range that is centered on the current target loadand whose limits are a predetermined percentage (e.g., 10%) greater thanand less than the target load. The primary smart crutch tip 820R may forexample provide a visual, auditory, or voice notification to urge thepatient 112 to put more weight or less weight on the injured lowerextremity when the target load on the walking aid is found to beexcessive or insufficient, respectively.

Operations 404, 406, and 408 may thereafter be repeated for each steptaken by the patient using the crutches 110. In the present embodiment,the primary smart crutch tip 820R does not store usage data for multiplesteps taken at various times during the time interval, nor is in thisinformation periodically communicated to any mobile patient app at apatient mobile device.

When the time interval expires (e.g., upon expiry of the countdowntimer), then the processor 952 may trigger an audible or visual usernotification indicative of that. The processor 952 may, alternatively orin conjunction, cause a prompt to be displayed on display 970 for entryof further user input via the user input mechanism 972. The prompt mayseek user input of a new target relative load on the injured lowerextremity and a new time interval of the rehabilitation period duringwhich the new target load on the walking aid is to be operative, e.g.,via fields 982 and 984 described above. Once these new parameters havebeen entered and accepted, the processor 952 may automatically recomputethe target absolute load on the walking aid for the specified timeinterval based on the earlier-specified patient weight and the newlyspecified target relative load. Thereafter, operation 400 may berepeated with the new target absolute load and for the newly specifiedtime interval. This may be repeated as many times as necessary for agiven rehabilitation period.

It will be appreciated that, although the electronic devices 120, 620,and 820 are referred to above as a smart “crutch tips”, the devices arenot necessarily used only with crutches. They could alternatively beinstalled onto, or be integrally formed with, other types of walkingaids, such as canes.

All references to a “doctor” in this document should be interpreted asbeing inclusive of any other medical professional who may be qualifiedto prescribed and monitor patient progress through a lower extremityrehabilitation program, such as a physical therapist for example.Similarly, all references to a “patient” in this document should beinterpreted as inclusive of any users of a walking aid as describedherein, regardless of whether the users are formally under the care of amedical professional at the time of use.

It will be appreciated that each memory 254, 754, and 954 describedherein constitutes a form of non-transitory, machine-readable medium,other forms of which may include magnetic or optical storage media.

Various alternative embodiments are possible.

As noted above, it is possible to use a smart crutch tip device 120,620, or 820 to monitor for patient compliance with a rehabilitationprogram when the walking aid comprises only one unit, such as a singlecrutch, rather than a pair. In this case, there would be no secondarysmart crutch tip. In the case of smart crutch tip 120 or 820, the soledevice would be installed onto the leg of the sole walking aid unit, asdescribed above, or in the case of smart crutch tip 620 would beintegrally formed therewith. The sole devices 120, 620, and 820 wouldnot receive wireless signals from any secondary smart crutch tip. In thecase of devices 120 and 620, wireless communication with the patientmobile device 130 would still occur.

In such a single-device scenario, operation 400 of the primary (andsole) smart crutch tip 120, 620, or 820 would still be as describedabove in FIG. 12 , with the following exceptions. Operations 404 and 406would not be performed according to the steps outlined in FIGS. 13 and14 respectively. Rather, operation 404 of FIG. 12 may entail only step410 of FIG. 13 , with step 412 being unnecessary. Moreover, referring toFIG. 14 , performing operations 420 and 422 would be unnecessary, andstep 424 would entail determining the peak load based solely on thedynamic load as measured by the primary smart crutch tip 120R, 620R, or820R during the patient step.

The above-described embodiments use a short-range wireless communicationtechnology, such as Bluetooth™, for transmitting dynamic loadinformation from the secondary smart crutch tip 120L, 620L, or 820L tothe primary smart crutch tip 120R, 620R, or 820R, respectively, in realtime. A short-range wireless communication technology (be it Bluetooth™or some other technology) may be used because the expected distancebetween the paired primary and secondary smart crutch tips during use isexpected to be well within the short-range communication limit of about10 meters.

The above-described embodiments further use a short-range wirelesscommunication technology, such as Bluetooth™, for communicating thecollective dynamic load on the pair of crutches 110 from the primarysmart crutch tip 120R or 620R to the mobile device 130 in real time. Itis possible that the distance between the mobile device 130 and theprimary smart crutch tip 120R or 620R could exceed a maximum range,e.g., if the mobile device 130 were left in another room from the smartcrutch tips. In that case, wireless communication between the primarysmart crutch tip 120R or 620R and the mobile device 130 may beinterrupted. Until communication can be reestablished, the primary smartcrutch tip 120R or 620R may buffer, e.g., in flash memory, collectiveload information for each step taken from the time at whichcommunication was interrupted. It is for this reason (at least in part)that a capacity of memory at the primary smart crutch tip 120R or 620Rmay be larger than memory capacity at the secondary smart crutch tip120L or 620L, respectively.

It is possible that a longer-range wireless communication technology(e.g., a medium or long-range technology) could be used forcommunication between the primary smart crutch tip 120R or 620R and themobile device 130 or possibly even for communication between thesecondary smart crutch tip 120L, 620L, or 820L and the primary smartcrutch tip 120R, 620R, or 820R, respectively. Longer range wirelesscommunication technology may reduce a risk of any loss of communicationbetween the devices, e.g., if real time user notification of load uponcrutches 110 is crucial for some reason. A tradeoff may be higher costof manufacture for smart crutch tips employing such longer-rangecommunication technologies.

Whatever wireless communication technology is used between these devices(be it short-range or otherwise) should avoid excessive lag. Lag may beconsidered excessive, e.g., if it prevents any requisite usernotification regarding load on the crutches 110 for the most recent stepfrom being provided at the primary smart crutch tip 120R before asubsequent step is taken. References to “real time” user notification inthis document may include near real-time (“near time”) usernotification, although any lag in user notification should not be soexcessive as to cause confusion over which patient step has triggeredthe user notification.

In the foregoing description, when a pair of smart crutch tips 120, 620,or 820 is used together, one of the devices is designated as primarydevice and the other is designated as the secondary device. For clarity,it is not required for the primary device to always be used on the rightside of the body of the patient and the secondary device on the leftside of the body. The positions of primary smart crutch tip andsecondary smart crutch tip relative to the body of the patient could bereversed. Moreover, the position of the primary smart crutch tiprelative to the injured lower extremity is immaterial.

In the description of system 100 above, the mobile patient app 132 atthe patient mobile device 130 is operable to receive rehabilitationprogram parameter data originating from doctor 116, the rehabilitationprogram parameter data including, for each of a plurality of timeintervals spanning a rehabilitation period, a target relative load foran injured lower extremity during the time interval relative to patientbody weight. The mobile patient app 132 also receives an indication ofthe patient body weight, e.g., directly from the patient 112 using themobile patient app 132. This information is used to generaterehabilitation program data 144 comprising a schedule for use by theelectronic device associated with the walking aid. The schedulespecifies the plurality of time intervals (e.g., days) spanning therehabilitation period and, for each of the time intervals, a targetabsolute load for the walking aid during the time interval. Thisrehabilitation program data 144 is output to the smart crutch tip 120,which uses it to automatically adjust a currently operative targetabsolute load on the walking aid over time according to the schedule.

It will be appreciated that the operations described in the precedingparagraph need not necessarily be performed at the patient mobile device130 in all embodiments. For example, in some embodiments, theseoperations could be performed at another computing device, such as thecloud-based server 160, the mobile doctor app 142, or the mobile doctorapp 152.

Other modifications may be made within the scope of the followingclaims.

What is claimed is:
 1. An electronic device for promoting proper use ofa walking aid during patient rehabilitation from a lower extremityinjury, the device comprising: a body having a receptacle configured toreceive a tip of a leg of the walking aid; a substantially cylindricalhousing configured to cooperate with the body to define an enclosedannular space; at least one load sensor anchored to the body, the atleast one load sensor being configured to measure a load on the walkingaid; a memory that, during device operation, stores rehabilitationprogram data defining: at least one time interval of a rehabilitationperiod; and for each of the at least one time interval, a target loadfor the walking aid during the time interval; a processor,communicatively coupled to the memory and to the at least one loadsensor, operable to: identify a currently operative time interval of theat least one time interval of the rehabilitation period; receive, fromthe at least one load sensor, data indicative of a dynamic load on thewalking aid during a patient step; determine, based upon the receiveddata, a peak load upon the walking aid during the patient step; andprovide a user notification indicating that the peak load upon thewalking aid during the patient step is non-compliant with the targetload for the walking aid for the currently operative time interval,wherein the memory and the processor are housed within the enclosedannular space; a retaining mechanism for retaining the tip of the leg ofthe walking aid within the receptacle; a base configured for limitedaxial movement relative to the body; and a foot at a lower end of thebase, wherein the at least one load sensor is disposed between the baseand the body and is configured to bear a load placed upon the walkingaid during use of the walking aid.
 2. The electronic device of claim 1wherein the walking aid is a pair of crutches or canes, wherein theelectronic device is a first electronic device associated with a firstcrutch or cane of the pair, wherein the data from the at least one loadsensor is indicative of a dynamic load on the first crutch or caneduring the patient step, and further comprising: a wireless transceiverconfigured to receive, from a second electronic device associated with asecond crutch or cane of the pair, wireless signals carrying dataindicative of a dynamic load on the second crutch or cane during thepatient step; and wherein the determining of the peak load upon thewalking aid during the patient step comprises: generating, based on thedata indicative of the dynamic load on the first crutch or cane and thedata indicative of the dynamic load on the second crutch or cane, arepresentation of a dynamic load on the pair of crutches or canescollectively during the patient step; and based on the generatedrepresentation, determining a maximum load on the pair of crutches orcanes during the patient step, wherein the peak load upon the walkingaid during the patient step is the maximum load on the pair of crutchesor canes during the patient step.
 3. The electronic device of claim 2wherein the data indicative of the dynamic load on the first crutch orcane includes first timestamp information, wherein the data indicativeof the dynamic load on the second crutch or cane includes secondtimestamp information, and wherein the generating of the representationof the collective dynamic load on the pair of crutches during thepatient step comprises; using the first timestamp information and thesecond timestamp information, time-aligning the data indicative of thedynamic load on the second crutch or cane with the data indicative ofthe dynamic load on the first crutch or cane; and summing the dataindicative of the dynamic load on the first crutch or cane with thetime-aligned data indicative of the dynamic load on the second crutch orcane.
 4. The electronic device of claim 1 wherein the receptacle isthreaded and wherein the retaining mechanism comprises: a threaded nut;and a split ring made from a resilient material; the nut and the splitring being configured so that, when the tip of the leg of the walkingaid is passed through both of the nut and the split ring and is receivedwithin the receptacle, threading of the nut onto the receptacle willcompress the split ring, causing the split ring to deform inwardlyagainst the leg of the walking aid to retain the tip of the leg withinthe receptacle.
 5. The electronic device of claim 1 wherein a durationof the rehabilitation period is longer than one day, wherein the atleast one time interval of the rehabilitation period is a plurality oftime intervals collectively spanning the rehabilitation period, andwherein the identifying of the currently operative time interval of therehabilitation period comprises: determining a current date; andchoosing one of the plurality of time intervals that includes thecurrent date as the currently operative time interval.
 6. The electronicdevice of claim 1 wherein the target load on the walking aid during thetime interval is a target absolute load on the walking aid during thetime interval and further comprising: a user input mechanism,communicatively coupled to the processor, for receiving user inputspecifying: a patient weight; a target relative load on an injured lowerextremity during the time interval, the target relative load beingrelative to the patient weight; and a duration of the time intervalduring which the target relative load on the injured lower extremity isto be operative, and wherein the processor is operable to compute thetarget absolute load on the walking aid based on the patient weight andthe target relative load on the injured lower extremity during the timeinterval.
 7. The electronic device of claim 6 wherein the processor isfurther operable to, upon expiry of the time interval during which thetarget relative load on the injured lower extremity is to be operative,provide a user indication indicating that the target relative load onthe injured lower extremity is no longer in effect.
 8. The electronicdevice of claim 7 wherein the user indication comprises a prompt forentry of further user input, via the user input mechanism, specifying: anew target relative load on the injured lower extremity; and a new timeinterval of the rehabilitation period during which the new target loadon the walking aid is to be operative.
 9. The electronic device of claim1 wherein the processor is further operable to store, in the memory,historical usage data comprising, for each of a plurality of previouslytaken patient steps, an indication of the determined peak load on thewalking aid during the patient step.
 10. A system for promoting properuse of a walking aid during patient rehabilitation from a lowerextremity injury, the system comprising: an electronic device associatedwith the walking aid, the electronic device comprising: a body having areceptacle configured to receive a tip of a leg of the walking aid; asubstantially cylindrical housing configured to cooperate with the bodyto define an enclosed annular space; at least one load sensor anchoredto the body, the at least one load sensor being configured to measure aload on the walking aid; a processor housed within the enclosed annularspace, the processor communicatively coupled to the at least one loadsensor; a retaining mechanism for retaining the tip of the leg of thewalking aid within the receptacle; a base configured for limited axialmovement relative to the body; and a foot at a lower end of the base,wherein the at least one load sensor is disposed between the base andthe body and is configured to bear a load placed upon the walking aidduring use of the walking aid; a computing device comprising a processorand memory storing instructions that, when executed, cause the computingdevice to: receive rehabilitation program parameter data originatingfrom a medical professional, the rehabilitation program parameter dataincluding, for each of a plurality of time intervals spanning arehabilitation period, a target relative load for an injured lowerextremity during the time interval, the target relative load beingrelative to a patient body weight; receive an indication of the patientbody weight; based on the rehabilitation program parameter data and thepatient body weight, calculate, for each of the plurality of timeintervals spanning the rehabilitation period, a target absolute load forthe walking aid during the time interval; and output rehabilitationprogram data comprising a schedule for use by the electronic deviceassociated with the walking aid, the schedule specifying: the pluralityof time intervals spanning the rehabilitation period; and for each ofthe plurality of time intervals spanning the rehabilitation period, atarget absolute load for the walking aid during the time interval,wherein the processor of the electronic device is operable toautomatically adjust, according to the schedule, a currently operativetarget absolute load on the walking aid by, periodically during therehabilitation period: based on a current date, identifying one of thetime intervals of the schedule as currently operative; using the atleast one load sensor, determining a peak load on the walking aid duringa patient step taken during the currently operative time interval; andproviding a user notification indicating that the peak load upon thewalking aid during the patient step is non-compliant with the targetabsolute load on the walking aid during the currently operative timeinterval.
 11. The system of claim 10 wherein the walking aid is a pairof crutches or canes, wherein the electronic device is a firstelectronic device associated with a first crutch or cane of the pair,wherein the data from the at least one load sensor includes dataindicative of a dynamic load on the first crutch or cane during thepatient step, and wherein the electronic device further comprises: awireless transceiver configured to receive, from a second electronicdevice associated with a second crutch or cane of the pair, wirelesssignals carrying data indicative of a dynamic load on the second crutchor cane during the patient step; and wherein the determining of the peakload upon the walking aid during the patient step comprises: generating,based on the data indicative of the dynamic load on the first crutch orcane and the data indicative of the dynamic load on the second crutch orcane, a representation of a dynamic load on the pair of crutches orcanes collectively during the patient step; and based on the generatedrepresentation, determining a maximum load on the pair of crutches orcanes during the patient step, wherein the peak load upon the walkingaid during the patient step is the maximum load on the pair of crutchesor canes during the patient step.
 12. The system of claim 10 wherein thecomputing device is a mobile device, wherein the electronic deviceassociated with the walking aid further comprises a wirelesstransceiver, and wherein the processor of the electronic deviceassociated with the walking aid is further operable to cause wirelesstransmission, to the mobile device, for each of a plurality of patientsteps taken during the rehabilitation period, of an indication of thedetermined peak load on the walking aid during the patient step.
 13. Thesystem of claim 12 wherein the mobile device comprises a display andwherein the processor of the mobile device is further operable to:store, in the memory of the mobile device, historical usage data of thewalking aid during the rehabilitation period, the historical usage dataincluding the indications of the determined peak load on the walking aidduring each of the plurality of patient steps taken during therehabilitation period; generate, based at least in part on thehistorical usage data, analytics indicative of the historical usage dataof the walking aid during the rehabilitation period; and display, on thedisplay of the mobile device, the generated analytics indicative of thehistorical usage data of the walking aid during the rehabilitationperiod.
 14. The system of claim 13 wherein the displayed analyticsindicative of the historical usage data of the walking aid during therehabilitation period include a graphical indicator, for a chosen timeinterval of the rehabilitation period, indicating a proportion ofpatient steps taken during the chosen time interval that were compliantwith the target absolute load for the walking aid during the chosen timeinterval.
 15. The system of claim 14 wherein the proportion of patientsteps is a first proportion of patient steps, the graphical indicator isa first graphical indicator, and wherein the displayed analytics furtherinclude: a second graphical indicator indicating a second proportion ofpatient steps taken during the chosen time interval that werenon-compliant with the target absolute load on the walking aid duringthe chosen time interval by virtue of insufficient load on the injuredlower extremity; and a third graphical indicator indicating a thirdproportion of patient steps taken during the chosen time interval thatwere non-compliant with the target absolute load on the walking aidduring the chosen time interval by virtue of excessive load on theinjured lower extremity.
 16. The system of claim 10 wherein thereceptacle is threaded and wherein the retaining mechanism comprises: athreaded nut; and a split ring made from a resilient material, the nutand the split ring being configured so that, when the tip of the leg ofthe walking aid is passed through both of the nut and the split ring andis received within the receptacle, threading of the nut onto thereceptacle will compress the split ring, causing the split ring todeform inwardly against the leg of the walking aid to retain the tip ofthe leg within the receptacle.